Real-World Data (RWD) on the 3-Year Follow-Up Outcomes of Different CNS Prophylaxis Strategies Across CNS-IPI Risk Groups in Patients With Diffuse Large B-Cell Non-Hodgkin Lymphoma

PURPOSE: CNS relapse in patients with diffuse large B-cell lymphoma (DLBCL) is associated with poor prognosis with a median survival of about 2.5 months. Data demonstrating best prophylactic strategy remain controversial and need further definition. PATIENTS AND METHODS: We present data of 110 patients with DLBCL treated with standard systemic therapy divided into four groups based on primary CNS prophylaxis strategy and CNS International Prognostic Index (IPI) risk categories. We compared their 3-year CNS relapse rate and overall survival in each group. RESULTS: The CNS prophylaxis strategy consisted of intrathecal (IT) methotrexate (MTX) in group 1, high-dose (HD) MTX in group 2, combination IT and HD MTX in group 3, and IT and/or HD MTX with intensive chemotherapy in group 4. At 3 years, CNS relapse rate was 8.6% (4/46), 8.3% (1/12), 4.8% (2/42), and 18% (2/11) in groups 1-4 (P = .64), respectively. According to CNS IPI, the CNS relapse rate was 16.6%, 10.1%, and 0% in high-, intermediate-, and low-risk groups, respectively. The 3-year overall survival rate was 69%, 75%, 80%, and 45% in groups 1-4 (P = .71), respectively. CONCLUSION: Our study while did not find statistical significance did indicate a lower incidence of CNS relapse with the addition of systemic HD MTX to IT MTX in the high-risk DLBCL population.